Air cooled brake shoe



Jan- 3, 1955 R. w. FOSTER 2,729,312

AIR ACOOLEJD BRAKE SHOE Filed Oct. 19, 1950 `.Fl- 3 4 {z INVENTOR..iiaffr I4( FaS/16W.

1,719,312 AitCoLj Btli siren' :notiert W'. Foefer, snuiven, tml'.Application october 19, 1950,-- serral No. 190,970

` Claims. (c'i. isszdi This invention relates to an air cooled brakeshoe,- andy more particularly to clamp anchoring means therefor adaptedte provide secure, durable connection. between the shoe and its holder.

This invention is an improvement over my co-pending application serialNo. 150,079' niet; en March rs, 195o, iv, abfandiid, and entitled Air Cled Brake Sl.

it n ttte primary @bien of this invention te provide rc'lioring r'iarlsfor the brake" sh clamp, f sch eliarctr that it not only tieners theeterne but as weltsertfes as a canopy' fe difesi an through an passagesinthe shoe. l,

Heretfo'r' it has liee'i th' practice in the art to provide cflaii'ipnlio'rin'g' il 'the' frfr'i of a longitudinally disposed, cat iie'tliilt. Thishpla't'e hasnorrnaily been o'illi stp'er'lic'illy ilddd i'upper face of uthe shoe, and lia's lerivf length siich that it spansbutsb'sfaitially th space 4 between the opposed holder sockets. As a res'ltof this construction and the stresses upon t-heu plate, the clampVanchored thereto has freuently beeqme loosened. As aAv consequence tlibrake s oe has either been impaired in its function or has at UnitedStates Patent O times been completely detached from its mounting. It

is obvious that there are many disadvantages and dangers that flow fromthe conventional construction. With applicants construction, on theother hand, the plate is firmly and relatively deeply imbedded in theupper face of the shoe. Furthermore, its length is so increased that itnot only spans the space between the opposed holder sockets but extendstherebeyond to a point outwardly of the shoe endsthemselves. Theprojecting plate ends are then formed into a type of scoop or canopywhich serves to direct the air through the air passages in the shoe Itis a still further object of this invention to provide improved airpassages over those disclosed in my aforementioned pending application.The importance and significance of such passages can not be overemphasized. As is well known, the friction of the brake shoe against thewheel generates a great amount of heat. As a result, the shoe tends todevelop ilaws in spots, and small slivers form on the braking surface.Since the slivers will fuse together, it follows that there will be areduction of the contact area between the shoe and the wheel.

In addition, the heat generated by friction in the conventional brakeshoe is such that the aforementioned metal plate is softened thereby. Asa result, it tends to bend. Furthermore, the heat causes the plate toexpand. As it cools it naturally contracts. WithY the bending, expandingand contracting of the plate there is a series of varying stresses andstrains upon the cast brake shoe. As a result the casting ultimatelycracks or breaks. Not only does this impair the effectiveness of theshoes but frequently renders them useless. Furthermore, there are knowninstances where a train or a car has been derailed by the falling of aportion of the brake shoe.

With applicants invention, the heat generated by the friction isdissipated so rapidly and to such an extent that the aforementioneddiiculties and dangers are eliminated.

n2,729,312 Patented Jan. 3, 1956 This is accomplished through theprovision of not' only longitudinally but transversely extending airpassages'. Furthermore, the passages are provided with such'- a conetour and configuration that the air is acceleratedY during passagetherethrough. As a result of the rapid rush therethroughf a constantsupply of cooling air, the heat is' effectively dissipated.-

It is a still further object of this invention to provide means inaddition to the aforementioned platev to anchor the elarnp which isfconnected to the brake shoe holder. This neafns is inthe form of riesh'which is fol-med iiil one or horizontal layers both above' and belowtheV air' pasJ sages.V The layers disposed above the pssage's haveceritralI cutout portions complementary to the ctnoutpr'` tions in theplate. As a result it is possible to east the clamp in the shoe in suchmanner' that tlie' of the clamp envelop not only the plate but tnelayersof ineen as iv'ell.l This results in the' clamp' beingl n'hl more'securely and durably anchored to' the Slide.

rnadd-itien to thev layers er horizontally disposed insh (the upper onesbeing utilized as mentioned above), there are prefemuly provided aplurality er vente ly disposed mesh elements. These are disposed onei-tl sfi'de of fll' longitudinal air passages. As a co'riseqe, thecas/ting is substantially' fortified.

A Tlte fell nature' of. the invention will be' understood from theaccompanying drawing and the following dscrip tion and claims.

In the drawing?,

Fig. t is a side elevation view' ofthe invention strewn in brakingass'efitien with t wheel or' a railway car.

Fig. 2 is a rep plan new of the Brake shoe.

Fig. 3 is a sectio View thereof taken n lilies er Eig. 2in die;direction of the arrows. L

Fig. 4 is a section new ftfereef taken on Beesd-'4"4 of Fig. 3 in thedirection of the arrows.

In the drawing, the truck of a railway car is indicated at 10. Pivotallysecured to the truck at 11 and depending therefrom on opposite sides ofthe car wheel 12 are the links or hangers 13. Pivotally carried by thelinks adjacent their lower extremities are the brake shoe holders 14.

The brake shoe is shown generally at 15 in Fig. 1 in braking engagementwith the wheel riding on the track 16. The shoe is of conventionalcontour, i. e. arcuate, and has a pair of opposed lugs 17 projectingupwardly at its extremities. Sockets are formed in the lugs to receivetherewithin the ends 18 of the holders.

It is, of course, essential that the shoe be securely connected to theholder. For that purpose there is provided the clamp 19 through which apin 20 of the holder extends. This clamp is transversely disposedrelative to the shoe and is located in the center thereof. This much isconventional. However, in order to assure that the clamp is rmlyanchored to the shoe, applicant provides not only the arcuate metalvplate member 21 having central cutout portions 22, but as well theexpanded metal elements or mesh 23. The mesh also has central cutoutportions complementary to those formed in the plate.

As will be observed particularly in Figs. 2, 3 and 4, at least twolayers of the mesh are disposed immediately below the plate. The freeends 24 of the clamp extend downwardly through the cutout portions ofthe plate and mesh and turn inwardly adjacent their extremities. Whenthe shoe is cast, the clamp will consequently be securely anchoredtherewithin. It is to be noted that the upper face of the plate and theside portions of the clamp projecting above the upper face of the shoeare covered by a substantial layer of the substance of which the shoe iscast. This fact also adds to the secure and durable anchoring of theclamp within the shoe.

In order that the shoe may be air cooled, there are provided a pluralityof longitudinally extending air passages 25 which open through the endwalls of the shoe. These passages preferably have a narrowed medial boreportion 26 in order that the air will be accelerated in its movementtherethrough. Extending transversely of the shoe are a series ofpassages 27 which also may have a centrally narrowed portion.

In order to direct and channel air through the passages, an air canopyor scoop 28 is formed at either end of the shoe in a plane above thelongitudinal passages. The scoops are preferably although notnecessarily the projecting ends of the plate 21 which is of such alength that said ends extend beyond the end walls of the shoe. As shownparticularly in Fig. 3, the projecting ends may be bent downwardly inorder to better guide the air into the passages although this is notnecessary. It is, of course, possible to provide similar air scoops forthe transverse passages.

The brake shoe is fortied by the addition of expanded metal or meshwhich may be disposed in layers 29 below the longitudinal passages andin one or more vertical layers 30 between and outside of said passages.

While the invention has been illustrated and described in great detailin the drawing and foregoing description, the same is to be consideredas illustrative and not restrictive in character.

The invention claimed is:

1. A brake shoe for railroad cars, and the like, including an elongatedgenerally arcuate brake shoe body adapted to conform generally to thecontour of the wheel with an engaging surface adapted to oppose thewheel, at least one longitudinal air passage formed therein, extendingfrom end to end and terminating in openings on the ends of the shoe, andair scoops connected to and extending beyond both ends of the shoe todirect air into the end of each passage.

2. The structure of clairn 1 characterized by and including a pluralityof transverse air passages formed in the shoe in communication with thelongitudinal air passages.

3. A brake shoe for railroad cars, and the like, including an elongatedgenerally arcuate brake shoe body adapted to conform generally to thecontour of a wheel with an engaging surface adapted to oppose the Wheel,at least one longitudinal generally open uid passage formed therein,extending from one end of the body to the other with a venturi in eachpassage positioned approximately intermediate the ends of the shoe.

4. The structure of claim 3 in which each passage is confined within thebody of the shoe.

5. The structure of claim 3 characterized by and including a pluralityof transverse fluid passages in the shoe.

6. The structure of claim 3 in which the passages are air passages andterminated in openings on the body of the shoe.

References Cited inthe tile of this patent UNITED STATES PATENTS 548,939Whitcomb Oct. 29, 1895 785,355 Gallagher Mar. 21, 1905 886,694 Gibbs May5, 1908 943,995 Reid Dec. 2l, 1909 984,253 Adriance Feb. 14, 1911995,013 Jones June 13, 1911 1,369,497 Thompson Feb. 22, 1921 1,498,983Schmidt June 24, 1924 1,510,825 Bousquet Oct. 7, 1924 1,715,806 WersallJune 4, 1929 1,921,836 Pogue Aug. 8, 1933 2,368,621 Tack Feb. 6, 19452,406,067 Eurit Aug. 20, 1946 FOREIGN PATENTS 19,951 Great Britain Sept.2, 1912 488,382 Great Britain July 6. 1938

